1. Field of the Invention
The present invention relates to a polymeric fluorescent substance, a polymer light emitting device (hereinafter, referred to as polymer LED) containing the same in an light emitting layer, and a device using the same.
2. Description of the Related Art
Light-emitting materials having higher molecular weight (polymeric fluorescent substance) are variously investigated since they are soluble in a solvent and can form a light-emitting layer in a light-emitting device by an application method, differing from those having lower molecular weight.
For example, a polymeric fluorescent substance containing a repeating unit derived from triarylamine (hereinafter, sometimes referred to as triarylamine type polymeric fluorescent substance) have been studied. JP-A9-255774 discloses those comprising a repeating unit derived from triarylamine and a repeating unit of polyether ketone. WO 99/20675 discloses those comprising a repeating unit derived from triarylamine and a repeating unit of fluorene.
However, the above known triarylamine type polymeric fluorescent substance still has been insufficient in quantum yield of fluorescence, and in light emitting efficiency when made into a device.
An object of the present invention is to provide a triarylamine type polymeric fluorescent substance which is excellent in quantum yield of fluorescence, and in light emitting efficiency when made into a device.